Learn more about common diagnostic studies
Explore different diagnostic studies used in treating spinal conditions.
Bone Scan is a study used to detect any inflammatory process in the body. When the source of pain is not clear the bone scan is able to direct the attention of your physician to the area inflammation. The inflammation may be caused by fracture, infection, tumor, or high bone turnover. However, the bone scan will not differentiate between these processes.
When inflammation is present, blood flow to that area increase in proportion to the inflammation. A radioactive marker is injected into a vein (through an IV), and the marker will travel to the area of inflammation. Time is allowed for the marker to reach the area of inflammation or high bone turnover. This takes approximately 3 hours. At that time, a scanner will detect the area in which there is a higher level of the marker and results will be printed on specialized paper. The images are obtained in a similar process to a CT Scan or an X-ray and the process is usually painless.
Since bone scans can not differentiate between different diagnoses, this test is usually followed by other tests like MRI, or CT scans. Furthermore, not all disease processes will be detected by bone scans. Old fractures are not always seen on bone scans as well as some tumors like Multiple Myeloma, certain thyroid, and certain breast cancers.
SPECT scan is a variation of the bone scan and is very sensitive for stress fractures of the spine (Spondylolysis). The SPECT scan is usually ordered for younger adults or teenagers to detect these stress types of fractures in the spine.
As our bodies age, we naturally lose bone mass. When the rate of bone loss is too high and there is substantial bone weakening, this condition is referred to as Osteoporosis. The rate of loss is different between individuals but there are definite trends in mineral bone loss. At risk are white, thin females who smoke and consume alcohol. Lowest risk is found in African American Males. In women, the risk increases after menopause with a decrease in Estrogen levels. Increased intake of Calcium and vitamin D may slow down the process but does not reverse it. New drugs have been introduced that reverses this process but very slowly over many years.
Several methods are available to measure bone density to evaluate the risk of fractures. Currently, the best method available is the DEXA Scan (Dual Energy X-ray Absorptiometry). It measures the density of vertebral bodies within the spine. The results are compared to healthy young individuals.
The exam is painless and lasts approximately 10 minutes with minimal radiation exposure. After interpretation of the study, steps can be taken to reduce the risk of a fracture.
Medications are now available to treat this condition. Fosamax is a drug introduced into the market to reverse the bone loss that is encountered with aging. This drug decreases the natural remodeling of bone and decreases the resorption of bone. Even though clinical studies show that the drug enhances bone mineral density, it may make bones more brittle since old bones remain without remodeling to produce new bone which occurs in normal conditions. Consult with your physician to learn if this medication is right for you. An alternative to Fosamax is Calcium and Vitamin D supplementation. This combination of medications does not increase bone mineral density but may slow down the resorption. In order to avoid osteoporosis, women at risk need to begin supplementation before the age of 30.
Nerve tissue conducts information about pain and sensation. It also transports signals for motor movements to the muscles. When pain or dysfunction sets in, it is often difficult to know the source of pain and malfunction. An EMG is an electrical study that measures the response of muscle to the stimulation of a nerve. A variation of this test is Nerve Conduction Velocity (NCV) which measures the speed of signal transport within the nerve.
By placing very small probes in the muscle tissue it is possible to make measurements and diagnose specific dysfunctions of nerves. It is also possible to pinpoint the area of the problem. As nerves pass through the extremity, there are several areas that the nerve could have impingements. These tests can help delineate the exact area and provide tactical information regarding treatment. This test can also differentiate between radiculopathy (nerve root compression) and neuropathy (nerve degeneration).
The test is mildly uncomfortable as the small needles are placed into the muscle tissue and last approximately one hour. No major risks exist, however, the results are operator dependent and not highly reliable.
A Myelogram is ordered by your physician to delineate some of the structures within your spinal canal. It uses X-ray and a contrast media (dye) to visualize the spinal canal, spinal cord, and nerves. Even though MRI technology is used more commonly, the Myelogram provides information that may be different than an MRI. Diseases that can be diagnosed with the Myelogram include disc problems, postoperative scarring, narrowing of the spinal canal (Spinal Stenosis), Spinal tumors, and inflammation.
Prior to the procedure, an IV will be placed by the staff and a mild sedative may be administered for patient comfort. The skin is numbed with an anesthetic solution and a larger needle is then placed into the spinal canal penetrating the envelope (dura) of the spinal cord. The dye is then injected and a series of X-rays are performed. Commonly a CT scan is performed to enhance visualization of the spinal elements. Any indentation in the dura or the nerve root will be visualized on the X-rays or the CT scan. The advantage of the Myelogram is the direct visualization of the indentations of the area in question.
- Please inform your physician if you are pregnant, think you might be, or you are breastfeeding.
- Inform him of any allergies you may have (X-ray dye or Iodine), seizure disorder, or the use of any antidepressant or anticoagulant (blood thinners) medications.
- Make arrangements to be taken home after the procedure. Driving is not permitted for two days after the procedure.
- Avoid any alcoholic beverages 2 days before and after the procedure.
- You may eat a light breakfast and drink prior to the procedure?.
- You must remain in bed the day of the procedure and the following day after the procedure.? Your head should be raised 30 degrees from a flat position. Avoid laying flat by using 3 pillows in propping your head.
- Continue taking your regular medications.
- Drink at least 8 glasses of liquids every day for 2 days.
Most common side effects from the procedure include:
- tightness in the back of the neck, shoulders, or lower back
- itching around the puncture area may also occur
Some patients may complain of headaches that last for several days. This may be caused by changes in the pressure of the Cerebrospinal fluid surrounding the brain and the spinal cord or by a reaction to the contrast media. This condition usually resolves on its own with bed rest and oral fluid intake. In rare instances, these headaches may be persistent and severe enough that other procedures become necessary to resolve these headaches. In almost all instances this complication eventually resolves. Other complications rarely include infections from penetration of the needle.
Inform your physician if you experience these problems for further evaluation and possible blood patch procedure. As with every test, risks, benefits, and alternatives should be evaluated. The benefits of the procedure must outweigh the risks and the results should carefully be evaluated by your spine surgeon.
Magnetic Resonance Imaging (MRI Scan) is a relatively new technology developed in State University of New York @ Brooklyn by Dr. Damadian. As compared to X-ray and CT scanning, there is no detectable radiation with the MRI. Although both soft tissue (including neural tissues) and bony tissue is seen by the MRI, the visualization of nerves and other soft tissues are superior.
The MRI uses a powerful magnet, radio waves, and a computer to produce detailed images of the body. MRI images are extremely detailed and so the results may be over-read. Research studies have indicated that images from normal people sometimes showed abnormalities as well. This produces some confusion. Due to this fact, every physician must correlate the MRI findings with the clinical symptoms of the patient in order to arrive at an accurate diagnosis. This is the origin of the common saying “treat the patient, not the images.”
During the exam, you will lay inside a tunnel-like structure while the computer collects the data to produce images. The process usually lasts about one hour. Some patients will experience anxiety from the tight space. Recently, the Open MRI was introduced which avoids this tight space. However, images produced by Open MRI systems are inferior to the traditional MRI scanners. If anxiety prevents you from obtaining the MRI scan, a referral to an Open MRI center can be made. During the exam, you will be able to communicate with the technologist through an intercom system. You should avoid any movement during the examination since this will distort the images and will produce inferior results. Recently, stand up MRI’s and flexion/extension MRI facilities have become available.
Because MRI uses a strong magnetic field, metallic objects may interfere with the scan. Contraindications to MRI scanning include the utilization of a pacemaker, aneurysm clips in the brain, inner ear implants, metal fragments in the eye, implanted spinal cord stimulator. If you are pregnant or think you may be, inform the technologist and your physician since a contrast may be injected intravenously to enhance the images. If you have anemia, other allergic respiratory disorders, asthma, and other allergic respiratory disorders, inform the technologist and your physician.
The images obtained from the MRI will be read by a trained radiologist and a report will be produced that is forwarded to your physician. Radiologists are specifically trained to read and interpret these studies, however, most spine surgeons prefer to look at the images in-person to maximize the obtained information. These images are also invaluable in diagnosis and preparation for any surgical procedure.
Computerized Tomography or CT scan is a commonly used technology that utilized X-ray with computer-managed software to produce cross-sectional images of the body. The produced images can be viewed on a screen and later printed on special paper for permanent records. Different types of images are produced by CT scan, however, bony details are better visualized than soft tissue anatomy. When there is a need to visualize and examine soft tissue structures (like discs, muscles, nerves, and tendons), MRI is usually a better test to request.
As the patient lays on the table, the scanner which is a large cylinder passes over the area of interest. Directions will be given by the technician while the images are produced. This test does not elicit any pain or discomfort as the images are taken. After the images are taken the patient is directed out of the room. Depending on the technique, a contrast may be injected by IV to enhance the images. On occasions, patients may have undergone other procedures prior to CT-scannings like Myelogram or Discogram.
Please inform the technologist if you are pregnant, might be pregnant, or breastfeeding. If you are allergic to any medications, iodine, contrast dye, or shellfish you should inform your physician and technologist. Although you may be asked to change into a hospital gown, wear comfortable clothing. Remove any metallic objects that may interfere with imaging. There are no contraindications to having pacemakers or metallic implants as is the case with MRI’s. The exam usually lasts about 30 minutes.
There are no immediate risks to the exam, however, as with any other X-ray procedure, the patient is exposed to radiation. Risks, benefits, and alternatives should be evaluated.
X-ray is the most commonly used diagnostic study used by the spine surgeon. It provides information regarding the alignment of the spinal column, the configuration of fractures, and the presence of tumors. It has a relatively low level of radiation and is comparably inexpensive. X-rays provide us with details regarding bony elements, but information regarding soft tissue structures is provided only indirectly. For this reason, our diagnostic studies may extend to the MRI, CT scan, or myelogram.
An array of other studies is available, helping us to pinpoint the diagnosis. The decision-making process in choosing the correct study will be performed by your physician who has the knowledge and experience to expedite your care with the least invasive studies that provide the most information.
X-rays are usually available in the office and the images can be viewed immediately. They are usually the first line of exam and are used routinely.